Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.53 (sialidase)
 2,694 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sugar specific lectins (PNA, RCA I, LPA, SBA, DBA, GSA IB4, GSA II, WGA, LTA, UEA I, Con A, LCA) with and without prior selective glycosidase digestion (sialidase, alpha-fucosidase, alpha-mannosidase, beta-N-acetylglucosaminidase, alpha- and beta-galactosidase, beta-glucosidase) were used in order to investigate the distribution of native accessible carbohydrates and obtain information dealing with the composition of terminal disaccharides within glycoconjugates present in acinar compartments and ductal segments of mammalian (mouse, rat, hare, and rabbit) parotid glands. Glycoconjugates containing variable amounts of mannose, glucose, N-acetylgalactosamine and N-acetylglucosamine were present in the parotid glands of all species. However, these carbohydrate chains exhibited a different composition of terminal sequences within each type of gland. For example, sialylated components having the terminal dimers sialic acid-galactose and sialic acid-N-acetylgalactosamine were found in all acinar cells, whereas fucoglycoconjugates with terminal disaccharide fucose-galactose were localized in the rat striated ducts and hare acinar cells. The terminal sequence alpha-galactose-beta-galactose was demonstrated in the mouse acinar cells. Finally, glycoconjugates characterized by the terminal dimer beta-galactose-N-acetylgalactosamine were demonstrated in the mouse acinar and ductal cells and the rat ductal ones. Thus, present findings outlined and further confirmed the possibility to elucidate the oligosaccharide structure in situ using lectin histochemistry combined with enzymatic degradation.
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PMID:Glycoconjugate composition of mammalian parotid glands elucidated in situ by lectins and glycosidases. 137 7

Sialoglycoconjugates were investigated in the bovine sublingual gland by direct visualization of sialic acid with specific lectins (LPA, SNA) and by histochemical procedures combined with sialidase digestion and lectins. The most reactive histological structures were found to be acini which contained glycoconjugates with terminal disaccharides consisting of sialic acid linked to galactose or N-acetylgalactosamine. Resistance to periodate oxidation was interpreted as demonstrating a relevant presence of C7, C8 and C9 acetylated sialic acids. KOH-Sialidase-DBA and KOH-Alcian blue sequences allowed the identification of C4 acetylated sialic acids.
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PMID:Variety of sialic acids occurring in the bovine sublingual gland. 789 45

The authors obtained small pieces of materials from portio vaginalis uteri of women being in postmenopause and premenopause, in different stages of pregnancy and parturition respectively after delivery. Biochemical investigations of these specimens were performed to study the background of physiological ripening of the uterine cervix. They examined the changes in activity of sialidase which cleaves terminal sialic acids. Investigations were performed with the use of Triticum vulgaris (WGA) and Limulus polyphemus (LPA) agglutinins (lectins) marked with FITC. These lectins bind specifically to the sialic acids. The evaluation of the lectin linkage was carried out with fluorescence microscope. Separately was evaluated the fluorescence of different extracellular matrix elements concerning the whole fluorescence of connective tissue as well. It was stated that the number of WGA- and LPA-binding sites of the uterine cervix compared to the non-pregnant state increases predominantly in the 1st trimester pregnancy. In relation to the 1st trimester we described a slight reduction of LPA- and WGA-binding sites in the 3rd trimester. The most impressing changes of LPA- and WGA-binding sites we observed during parturition in the extracellular matrix. These results coincide with the author's previous experience whereas the sialidase activity increases significantly during parturition. These data support the assumption that the terminal sialic acids and the sialidase play certain role in human uterine cervix during the gestational process. Their role at the time of pregnancy and delivery however remains to be cleared.
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PMID:Changes in binding capacity of sialic acid-specific lectins in the connective tissue of the uterine cervix during its physiological maturation. 797 94

The authors obtained small pieces of materials from portio vaginalis uteri of 122 women being in postmenopause and premenopause, in different stages of pregnancy and parturition concerning directly after delivery. Different biochemical investigations of these 30-200 mgs specimens were performed to study the physiological background of its ripening process. They examined the changes in activity of sialidase which cleaves terminal sialic acids. The authors performed these investigations with the use of Triticum vulgaris (WGA) and Limulus polyphemus (LPA) agglutinins (lectins) marked with FITC. The evaluation of the lectin linkage happened with fluorescence microscope. They evaluated the whole fluorescence of extracellular matrix but separately of different extracellular matrix elements as well. From their investigations was stated that the number of WGA and LPA binding sites of the uterine cervix increases predominantly in the 1st trimester pregnancy compared to the non-pregnant state. As compared to the 1st trimester they described a slight reduction of LPA- and WGA-binding sites in the 3rd trimester. The most impressing changes of LPA and WGA binding sites in the extracellular matrix were observed during parturition. These results coincide with the authors' previous experience whereas the sialidase activity increases significantly during parturition. These data support the assumption that the terminal sialic acids and the sialidase play a recently yet not cleared role in the ripening of the human uterine cervix during pregnancy and in dilatation at the time of parturition.
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PMID:[Sialidase activity in cervical connective tissue during cervix maturation and dilatation during labor]. 817 99

The human red blood cells with phenotype En(a-) were characterized by the lack of MN antigens. The red blood cells with phenotype En(a-) which were found in a Japanese family were tested to clarify the changes in membrane surfaces of the red blood cells during in vivo ageing. The contents of sialic acid, glucose, mannose, galactose, fucose, N-acetylglucosamine and N-acetylgalactosamine of the red blood cell membranes obtained from the old red blood cells with phenotype En(a-) were significantly lower than those of the young red blood cell membranes. Neither the young nor the old red blood cells with phenotype En(a-) showed the agglutination with Arachis hypogaea (PNA) which was capable of binding to T agglutinogen. It is presumed that En(a-) red blood cells are not exposed to sialidase in vivo. In comparison with the young En(a-) red blood cell membranes, the number and the distribution density of lectin receptor sites on the old ones for Limulus polyphemus (LPA), Canavalia ensiformis (Con A), Triticum vulgaris (WGA) and Bauhinia purpurea (BPA) were significantly lower. It is thought that En(a-) red blood cell ageing is accompanied by elimination of some sialoglycoconjugates which have affinity for LPA, Con A, WGA and BPA, whereas En(a-) red blood cells lack glycophorin A.
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PMID:Changes in En(a-) human red blood cell membranes during in vivo ageing. 886 34